1. Field of the Invention
Embodiments of the present invention generally relate to hard drives and, more particularly, to a method for saving power during seeks of hard drives.
2. Description of the Related Art
In past hard drive systems, actuators would be run at full power for every seek required. Even if a longer seek time was associated with a given command, the actuator of the hard drive would run at full power to try and position itself for reading the information as quickly as possible. However, if given a longer rotation time, the actuator has a longer time to position itself in the correct area and could be moved at less than full power.
A method called Just-in-Time (or JIT) was developed to capture this power saving idea. In the first applications of JIT only one level was implemented which decreased acceleration time and thus the velocity of the actuator in the hard drive for longer seek times and thus saved power. In later versions, 4 levels of JIT were implemented allowing for further power saving possibilities. If a seek time was deemed to be within a given JIT level's seek time range the actuator would be limited to a predetermined velocity, associated with that JIT level, thus slowing the actuator to save power. In order to realize even further power savings, the number of JIT levels needs to be increased. However, adding more predetermined JIT levels increases table size and the time required to create, and adjust, table entries.
This presents the need for a method that can add further levels of power saving capability without increasing used space and while maintaining a high level of efficiency.